1. Field of the Invention
The present invention relates generally to a roof airbag apparatus which can reduce passenger injuries and, more particularly, to a roof airbag apparatus which supports an airbag cushion so that the airbag cushion can be smoothly and reliably deployed in a correct direction.
2. Description of Related Art
Generally, airbag systems are classified into a driver seat airbag which protects a driver, a passenger seat airbag which protects a passenger sitting in the passenger seat, and a side airbag and a roof airbag.
Furthermore, such an airbag system includes an impact sensor which senses impact to the vehicle, an airbag controller which determines whether the airbag should be deployed based on information transmitted from the impact sensor, and an airbag module which operates the airbag cushion depending on the determination of the airbag controller. That is, when the impact sensor senses a vehicle collision, the signal is transmitted to the airbag controller. The airbag controller operates an inflator of the airbag module, so that the airbag cushion is instantaneously inflated to protect a passenger in the case of impact.
However, in the conventional techniques, in the case where the volume of the airbag cushion is relatively small, when the passenger strikes the deployed airbag cushion, the airbag cushion may be torn by shear force, or it may not effectively absorb impact energy because it is deployed or rotated in an incorrect direction.
Furthermore, in the case where the volume of the airbag cushion is relatively large, an area over which the airbag cushion comes into contact with the vehicle roof is sufficiently large, so that the airbag cushion can be prevented from being torn or rotating. However, to increase the volume of the airbag cushion, the capacity of the inflator as well as the airbag cushion is increased, with the result that the weight of the product and the production cost are increased.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.